Influence of post-harvest processing on ochratoxin A content in cocoa and on consumer exposure in Cameroon

Ochratoxin A (OTA) is a mycotoxin that contaminates several foodstuffs, including cocoa. It has nephrotoxic, teratogenic and carcinogenic properties in humans. The effect of post-harvest processing and storage on the OTA contamination of cocoa was studied over three successive cocoa seasons (2005, 2006 and 2007) in Cameroon. The type of fermentation (box or heap) did not significantly influence bean OTA content, which varied from undetectable (<0.03 ng/g) to 0.25 ng/g, remaining below 2 ng/g (the defined standard for cocoa beans). However, pod damage and late pod opening were aggravating factors for OTA contamination of cocoa. If pods were not intact (intentionally or naturally damaged), OTA was found in samples with contents of up to 75.5 ng/g before processing and 32.2 ng/g after 4 months' storage. This contamination exceeded the levels tolerated for export. In addition, some of the cocoa produced is processed locally and consumed as chocolate, cocoa powder, chocolate filled sweets, cocoa-based drinks and cocoa butter. In Cameroon, the average daily consumption of cocoa by-products is estimated at 0.75 g/d for adults and 1 g/d for children. Consequently, for maximum OTA contamination of cocoa beans, the maximum daily exposure to OTA would be 1.61 ng/kg bw/d in young children weighing around 20 kg, greatly contributing to the exposure of young consumers.